The present invention relates to a method for reducing microorganisms in the environment of newly hatched poultry which reduces the chance of transmission of disease in the hatchery.
The environment of newly hatched poultry quickly becomes contaminated with microorganisms as soon as the actual hatching process or exit from the eggs begins. The microorganisms include, but are not limited to, (1) bacteria such as Salmonella species, Escherichia coli, staphylococcus aureus and (2) fungal organisms such as members of fungal genus Aspergillus, and possibly avian Mycoplasmas. This rapid rise in the concentration of microorganisms is often referred to as a bacterial bloom which follows the pipping stage of incubation in poultry. It is at his stage that optimum conditions for growth of microorganisms exists in terms of humidity, temperature, and nutrient levels. Organic debris present from the hatching process provides abundant levels of nutrients enhancing microbial replication at this time.
The microbial levels in this environment are commonly measured by microbiological culture of air or by measurement of microbial levels contained on specific quantities of hatcher down or fluff (a by product of the bird produced during hatch).
The method required by government regulation for at least the last 40 years to reduce this environmental contamination is to generate formaldehyde gas by either physically mixing formalin with potassium permanganate, or more conveniently by evaporating formalin on a continuous basis during the last few days of the hatching process. While the use of formaldehyde does reduce the level of microorganisms in the environment it is becoming more difficult to use due to the public health concerns about exposure of humans to this compound.
Another significant concern with the use of formaldehyde in the post pipping stage of hatching is the adverse effect of this compound of the physical integrity of the avian respiratory system. Published literature documents this affect. The physical damage caused to the avian respiratory system by formaldehyde may predispose the animals to increased susceptibility to respiratory disease encountered in the early days of life.
It will be understood that while the invention has application to the environment of avian chicks after they are hatched and that the method in accordance will affect the portion of chicks that survive. Thus, one effect of the use of the method in accordance is to improve the hatchability of eggs since that term is defined as the portion of chicks that survive the hatching process.
The incubation process in commercially raised-avian species such as chickens and turkeys is conventionally carried out initially in setters and then in a type of incubator referred to as a hatcher. In the hatcher the respiratory system of the embryo converts to a direct air breathing animal (the pipping stage), as opposed to air exchange across the egg shell. The control of temperature and humidity are especially critical at this point of hatching. Levels of moisture too high or too low will interfere with the hatching process and result in decreased hatch percentage and or inferior post hatch performance of hatched poultry.
It is because of this that a gaseous disinfectant such as formaldehyde is desirable because it can be administered continuously from the point of pipping when the microorganism bloom occurs up until essentially all the poultry have exited from the egg without significantly increasing the moisture level in the environment. The time for this to happen may be up to thirty hours which precludes conventional methods of disinfectant application such as spraying, conventional automatic foggers or even continuous administration through the hatcher humidifying system. All of these methods would produce humidity levels too high when used on a continuous basis resulting in a smaller percentage of chicks surviving the hatching process or poor post hatch performance.
The prior art includes U.S. Pat. No. 4,932,359 which discloses a process for sanitizing eggs by exposing the eggs to a solution of hydrogen peroxide during one or more stages of the hatchery process. The teachings of that patent are expressly limited to application until the actual time of pipping and hatching. Thus, there is no teaching of application after pipping. It is an object of the invention to have a method which will provide continuous protection for commercially raised poultry from the time the birds first break through the egg shell until they are removed from the hatchery environment.
It is still another object of the invention to provide such a method to decrease environmental microbial contamination without adversely affecting the proportion of birds that survive the hatching process.
It is another object of the invention to provide a method to accomplish the above which would not adversely affect the post hatch performance of the poultry.